redux-restate/lib/index.js

<div align="center"> <h1>redux-restate</h1> <br/> <img src="https://cdn.rawgit.com/theKashey/restate/1d67d86d/images/logo.svg" alt="restate" width="600" align="center"> <br/> <br/> Restate base layer. <br/> <br/> <a href="https://circlec

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _symbolObservable = require('symbol-observable');

var _symbolObservable2 = _interopRequireDefault(_symbolObservable);

var _shallowequal = require('shallowequal');

var _shallowequal2 = _interopRequireDefault(_shallowequal);

var _observable = require('./observable');

var _observable2 = _interopRequireDefault(_observable);

var _subscribe = require('./subscribe');

var _subscribe2 = _interopRequireDefault(_subscribe);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

var replaceReducer = function replaceReducer() {
  throw new Error('Dont call replaceReducer on synthetic store.');
};

var getDispatches = function getDispatches(stores) {
  var result = {
    called: null,
    returnedValue: null,
    next: Object.keys(stores).reduce(function (acc, storeKey) {
      acc[storeKey] = function (event) {
        result.called = storeKey;
        result.returnedValue = stores[storeKey].dispatch(event);
      };
      return acc;
    }, {})
  };
  return result;
};

var getStates = function getStates(stores) {
  return Object.keys(stores).reduce(function (acc, storeKey) {
    acc[storeKey] = stores[storeKey] && stores[storeKey].getState();
    return acc;
  }, {});
};

var restate = function restate(stores, createState, onDispatch) {
  var _ref;

  var initialOptions = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : {};

  var options = initialOptions;
  if (typeof createState !== 'function') {
    throw new Error('Please provide a createState function');
  }

  if (typeof onDispatch !== 'function') {
    throw new Error('Please provide a onDispatch function');
  }

  var nextState = function nextState(oldState) {
    return createState(getStates(stores)) || oldState;
  };

  var currentState = nextState({});

  var updatePending = false;
  var subscriptions = [];

  var _createSubscription = (0, _subscribe2.default)(),
      subscribe = _createSubscription.subscribe,
      trigger = _createSubscription.trigger;

  var dispatch = function dispatch(event) {
    var dispatchers = getDispatches(stores);
    onDispatch(dispatchers.next, event);
    if (!dispatchers.called) {
      console.error('No next dispatch was called at', onDispatch);
      throw new Error('No next dispatch called');
    }
    return dispatchers.returnedValue;
  };

  var getState = function getState() {
    return currentState;
  };

  var areStatesEqual = function areStatesEqual(prev, next) {
    var areEqual = options.areStatesEqual && options.areStatesEqual(prev, next);
    return typeof areEqual === 'undefined' ? (0, _shallowequal2.default)(prev, next) : areEqual;
  };

  var onStateUpdate = function onStateUpdate() {
    if (options.async) {
      if (!updatePending) {
        updatePending = Promise.resolve().then(function () {
          updatePending = null;
          trigger();
        });
      }
    } else if (options.onUpdate) {
      options.onUpdate(trigger);
    } else {
      trigger();
    }
  };

  var triggerUpdate = function triggerUpdate() {
    var lastState = currentState;
    currentState = nextState(currentState);
    if (!areStatesEqual(lastState, currentState)) {
      onStateUpdate();
    }
  };

  var initialize = function initialize() {
    Object.keys(stores).filter(function (key) {
      return stores[key];
    }).forEach(function (storeKey) {
      return subscriptions.push(stores[storeKey].subscribe(triggerUpdate));
    });
  };

  var unsubscribe = function unsubscribe() {
    subscriptions.forEach(function (unsubscribe) {
      return unsubscribe();
    });
  };

  var replaceOptions = function replaceOptions(newOptions) {
    options = _extends({}, options, {
      newOptions: newOptions
    });
  };

  if (!options.noAutoSubscribe) {
    initialize();
  }

  return _ref = {
    dispatch: dispatch,
    subscribe: subscribe,
    getState: getState,
    replaceReducer: replaceReducer
  }, _defineProperty(_ref, _symbolObservable2.default, (0, _observable2.default)(subscribe, getState)), _defineProperty(_ref, 'unsubscribe', unsubscribe), _defineProperty(_ref, 'initialize', initialize), _defineProperty(_ref, 'update', triggerUpdate), _defineProperty(_ref, 'replaceOptions', replaceOptions), _ref;
};

exports.default = restate;